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1. Configuring Motion Sensor with Raspberry Pi Pico

Configuring Motion Sensor with Raspberry Pi Pico

The Raspberry Pi Pico has various GPIO pins which we can use as input or output. It is can be easily done by configuring the GPIO in the codes. In this tutorial we will learn to interface a motion sensor with Pico board. We will use python code to configuring Motion Sensor with Raspberry Pi Pico. Before we jump into this tutorial, if you are new then you can get the basics of the Raspberry Pi Pico in our Raspberry Pi Pico Set Up Guide.

Raspberry Pi Pico is really good for micro python based standalone projects. It is much more faster then Arduino.

Things Required

Below components are required to build the project

Breadboard x 1
LED (Any Color) x 1
Resistor 330 Ohm x 1
PIR Sensor x 1
Jumper wires

Working

The Passive Infrared (PIR) sensor will detect the motion and it will trigger the LED and buzzer for audio indication. Passive Infrared sensor is commonly used in home security systems. This is a simple project which will perform as a motion sensor alarm.

Breadboard Connection

The connection is simple on a Breadboard. You can also use a plain PCB and solder the components as per the diagram below.

Code Analysis

Below libraries help us to communicate with the GPIO and to control them.

import machine
import utime

Here LED is connected to GPIO 15 of Raspberry Pi Pico which is physically pin 20 in the board. This is configured as a output pin.

led = machine.Pin(15, machine.Pin.OUT)

The PIR is connected to GPIO 28 which is physical pin 34 of Raspberry Pi Pico. It is configured as in input with machine.Pin.IN. We are also setting the Pico’s internal resistor to pull down. This will help Pico to read the value as zero, until PIR sensor triggers it. We are using machine.Pin.PULL-DOWN to configure it.

pir = machine.Pin(28, machine.Pin.IN, machine.Pin.PULL_DOWN)

For configuring the buzzer we have connected it with GPIO 14, which is physical pin 19 of raspberry Pi Pico. It is set as output pin.

buzzer = machine.Pin(14, machine.Pin.OUT)

To ensure there is no false trigger of alarm at the beginning of the project we have placed the small delay. This also helps the sensor to settle down before it starts.

utime.sleep_ms(100)

An IRQ (interrupt request) is configured to trigger the pir_handler function. GPIO28 gets activated when the PIR triggers the signal.

pir.irq(trigger=machine.Pin.IRQ_RISING, handler=pir_handler)

Complete Code

You can download the code from the below link. Unzip it and open it using Thonny IDE. You can download if it is not installed and use this guide to upload the code using Thonny IDE using Raspberry Pi PICO.

Building and Testing

Once you have connected the components as per the connection diagram and uploaded the code, Now its time to test it. To run the code in Thonny IDE just click on the Green Play button. Initially it will trigger the alarm and toggles the LED and buzzer on and off for sometime and then it will settle down.

Once you move near the PIR sensor it will trigger the alarm again and after a small delay of 10 seconds it will stop. This concludes your project is working fine.

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Summary

We have connected a PIR motion sensor with Raspberry Pi Pico. We have used micro python code in this project. Along with PIR sensor we have used a LED and a buzzer for audio visual indication of this motion alarm. Any beginner can build this project and start with micro python based projects. Hope you like this project and don’t forget to share this article with others.